Bicuspid Valve Aortopathy: Feasibility of a Comparative Effectiveness Study

描述(申请人提供)：多达300万美国人已经或将要在二尖瓣主动脉瓣的设置中胸主动脉扩大，即使在瓣膜功能正常的情况下。进行性扩张和主动脉夹层可能导致灾难性后果。有时会采用药物治疗来减缓进行性增大，但从未在临床试验中进行过测试。最好的候选药物是β受体阻滞剂或血管紧张素受体阻滞剂，主要是基于对其他影响主动脉的血管疾病的新兴经验。需要研究来确定这两种策略是否都比不治疗更好。理想的研究应该是一项随机临床试验，测试各种治疗方案的实用效果，尽管这样的试验需要足够的试点数据来进行适当的规划。我们假设一种方法的优越性是可以证明的。为了获得未来试验所需的试点数据和经验，我们提出了这一可行性方案，其具体目标是：1)量化参与医疗中心和周围诊所的所有二尖瓣患者中符合未来试验条件的患者的患病率；2)确定处方习惯和患者对当前采用的各种治疗策略的依从性；以及3)量化目标人群主动脉面积随时间的变化。这项为期三年的有限可行性研究将收集所有二叶主动脉瓣患者的信息，对符合条件的患者进行前瞻性跟踪，其中包括60名在22-24个月期间接受连续磁共振检查以测量主动脉面积变化的患者。

DESCRIPTION (provided by applicant): As many as 3 million Americans have or will have an enlarged thoracic aorta in the setting of a bicuspid aortic valve, even when valve function is normal. Progressive dilatation and aortic dissection may result with catastrophic consequences. Medical therapy is sometimes adopted to attenuate the progressive enlargement, but has never been tested in clinical trials. The best pharmacologic candidates are beta blockers or angiotensin receptor blockers, mainly based on emerging experience in other vascular conditions affecting the aorta. Research is needed to determine whether either strategy is superior to no treatment. The ideal study would be a randomized clinical trial testing the pragmatic effectiveness of the various treatment options, although such a trial requires adequate pilot data for proper planning. We hypothesize that superiority of one approach can be demonstrated. In order to obtain the necessary pilot data and experience for a future trial, we propose this feasibility protocol with the specific aim to: 1) quantify the prevalence of eligible patients for a future trial from all bicuspid valve patients seen at participating medical centers and surrounding clinics, 2) determine prescribing habits and patient compliance with various treatment strategies currently employed, and 3) quantify variance of change in aortic area over time for the target population. This limited three year feasibility study will gather information o all patients with a bicuspid aortic valve, from which eligible patients will be followed prospectively, including 60 patients undergoing serial MRI over 22-24 months to measure change in aortic area.